The present invention relates to an inductive electronic module according to the preamble of the main claim as well to the use of such an electronic module; a generic module is known from the US 20050286270.
Transformers have been disclosed in the art where windings are formed on the limbs of an (approximately e-shaped) core element. A typical e-shape therefore forms an inner limb as well as two lateral limbs adjacent to the inner limb. Depending on the respectively provided transformer or transducer functionality these then have limb windings associated with them.
Furthermore it is known from the state of the art to implement transformers as so-called planar transformers by implementing the windings (typically provided stacked and suitably connected) in the form of conductor tracks on printed circuit boards. Such planar inductivities then cooperate with a core element formed for example of ferrite which engages in an breakthrough of a winding shaped as a “printed” coil on an associated circuit board. This approach in particular permits automated manufacture or manufacture in bulk.
In the context of complex circuit topologies which use a plurality of transformers or transducers, this, of necessity, leads to the need for a more efficient implementation and a reduction in the amount of components used, in particular in the context of the above mentioned planar technology. As an example for the use of such a technology in this context reference is made to the German patent application 10 2010 010 235 of the applicant, which, in view of the technological context described in there as an application for the present invention, shall be deemed to be part of the disclosure as belonging to the invention, and which discloses a control device for a plurality of LED strands (as consumers), which are acted upon by preferably the same predetermined split current. In essence this application provides for suitable transformers for each of these branches, wherein for a traditional implementation, in particular for a large number of branches or strands to be supplied with a predetermined split current in the manner described in there, a corresponding plurality of transformers is required. For a typical implementation in planar technology, these transformers have, of necessity, to be designed at great expense accompanied by a corresponding space requirement, resulting in the need to reduce the amount of components required for transformers in circuit topologies of this kind (and, of course, beyond it).
The use of an inactive electronic module for operating a plurality of LEDs arranged in the form of a strand is known moreover from the US 2006/0255753.
Accordingly it is a requirement of the invention to improve a generic inductive electronic module for implementing a transformer, in particular in planar technology, in such a way that a required component amount can be reduced for a plurality of transformers, the number of required core elements, in particular, can be reduced and, in the context of a planar technology, the required circuit board area can be reduced.
The requirement is met by the inductive electronic module having the characteristics of the main claim; advantageous further developments of the invention have been described in the sub-claims. Also, protection is claimed within the framework of the present invention for use of the inductive electronic module according to the main claim as well as the further developing sub-claims in respect of a current divider device, on which a current generated on the secondary side of a first transformer is split among at least two independently controlled consumer branches each comprising a transformer. Whilst the present invention is suited, in particular, to the current-driven control of LED series connections in their role of consumers, the present invention is nevertheless not restricted to these but rather is suitable for any application purposes where a plurality of transducers or transformers have to be implemented in an efficient manner using a minimum number of core elements. Within the framework of the present invention this applies, preferably, to implementations by means of planar technology, although in this context also the present invention is not restricted with respect to the range of applications.
According to the invention the inductive electronic module advantageously achieves a magnetic coupling between the first winding and the second winding with the result that each of these windings (each of which has a plurality of magnetically coupled, separately contactable conductors) is able to implement a transducer or transformer without the transformer implemented by the first winding (or a pair of conductors existing therein) magnetically influencing a transformer of the second winding.
According to the invention this is implemented in that the first winding is provided in the form of a series connection made up of two partial windings on two of the lateral limbs, in particular opposite each other in relation to the inner limb, i.e. in that it is implemented as a winding by means of two consecutively connected sections. The second winding, by contrast, is formed on the inner limb. With regard to the magnetic flows implemented by the windings according to the invention in the core element this can have the advantageous effect that a magnetic flow caused in the inner limb by the first winding (or the two partial windings on the lateral limbs) is cancelled or becomes zero in order to prevent the second winding formed on the inner limb from becoming magnetically influenced. As a result of the invention this advantageously leads to one and the same core element being able to form at least two transformers independent of one another, i.e. when the first winding implements a first transformer having a corresponding plurality of separately contactable conductors and the second winding (again having a plurality of conductors) implements a second transformer which is then, according to the invention, magnetically decoupled from the first transformer and is independent.
Whilst, as generally indicated above, it would be possible for this approach to the solution to be implemented discretely in principle on a core element body by means of suitable coils, it is nevertheless preferable in terms of the invention to use planar technology for implementing the invention. For this purpose the first and second windings are formed as an array of conductors on (at least) one circuit board, wherein the core elements then engage in breakthroughs or recesses in the circuit board in the area of the conductor windings. In order to achieve the desired inductivities the winding (with its details) may then be implemented as a multi-layer winding with suitable vertical contacting such as in the form of known multi-layer circuit boards, or by additionally or alternatively using a plurality of single circuit boards suitably stacked and with through-connections according to the tracing of the conductors.
When using planar technology for implementing the present invention it is especially favourable and preferred to manufacture a transformer by arranging for at least two conductors of one of the windings to be traced in parallel and/or concentrically on a circuit board; in this way it is possible to predefine the winding structure exactly and so as to be easily reproducible but due to the areal layout the respectively desired magnetic coupling can also be easily configured thus allowing for a cost-effective manufacture in batches.